Preparation and Properties of Vegetable-Oil-Based Thioether Polyol and Ethyl Cellulose Supramolecular Composite Films

Ethyl cellulose(EC),an important biomass-based material,has excellent film-forming properties.Nevertheless,the high interchain hydrogen bond interaction leads to a high glass transition temperature of EC,which makes it too brittle to be used widely.The hydroxyl group on EC can form a supramolecular system in the form of a non-covalent bond with an effective plasticizer.In this study,an important vegetable-oil-based derivative named dimer fatty acid was used to prepare a novel special plasticizer for EC.Dimer-fatty-acid-based thioether polyol(DATP)was synthesized and used to modify ethyl cellulose films.The supramolecular composite films of DATP and ethyl cellulose were designed using the newly-formed van der Waals force.The thermal stability,morphology,hydrophilicity,and mechanical properties of the composite films were all tested.Pure EC is fragile,and the addition of DATP makes the ethyl cellulose films more flexible.The elongation at the break of EC supramolecular films increased and the tensile strength decreased with the increasing DATP content.The elongation at the break of EC/DATP(60/40)and EC/DATP(50/50)was up to 40.3%and 43.4%,respectively.Noticeably,the thermal initial degradation temperature of the film with 10%DATP is higher than that of pure EC,which may be attributed to the formation of a better supramolecular system in this composite film.The application of bio-based material(EC)is environmentally friendly,and the novel DATP can be used as a special and effective plasticizer to prepare flexible EC films,making it more widely used in energy,chemical industry,materials,agriculture,medicine,and other fields.

TEMPERATURE DEPENDENCE OF AIR SEPARATION OF LIQUID CRYSTALLINE TRIHEPTYL CELLULOSE/ETHYL CELLULOSE MEMBRANES

Triheptyl cellulose/ethyl cellulose(3/97)binary blend membranes were prepared from tetrahydrofuran,chloroform and dichloromethane solutions and their air separation capabit- ities were studied at different temperatures.With increasing temperature from 25 to 85℃,the flux QOEA of O_2-enriched air(OEA),O_2 permselectivity and the O_2 concentration Yo_2 in the OEA all increase.The membranes show a unique trend in their Yo_2～QOEA relationship,that is,the air separation capability increases simultaneously with the OEA permeation capability.The magnitudes of QOEA and Yo_2 for 17μm-thick membrane after the testg time of 36hours at 70℃ are 5×10^(-4)cm^3 (STP)/s·cm^2 and 37.6%,respectively.The air separation capability depends slightly on membrane forming solvents.

Interfacial Properties of Ethyl Cellulose/Cellulose Acetate Blends by HPLC

The high performance liquid chromatography method (HPLC) with ethyl cellulose/cellulose acetate (EC/CA) blends and EC as column packing material, and small molecular weight compound as probe molecules was employed to measure the retention volume (VR) and equilibrium distribution coefficient (K) of both inorganic and organic solutes. The interfacial separation properties of EC/CA blends were characterized by the HPLC data. The effects of the blends on the interfacial adsorption properties, hydrophilicity, affinity, polar and non-polar parameters of EC membrane materials were studied subsequently. The research results indicate that the interfacial adsorption properties and hydrophilicity of EC have been improved by solution blending with CA. The alloys are superior to EC in the separation efficiency for non-dissociable polar organic solute. The EC/CA alloy (80:20, ω) is suitable for desalting and desaccharifying.

FIBRE-FORMING OF ETHYL CELLULOSE IN POLYPROPYLENE MELT

Ethyl cellulose (EC), taken as a thermotropic liquid crystalline polymer, was blended with polypropylene (PP), followed by injection molding. Fibre-forming of EC in the PP matrix is analyzed,based on the rheological data,dynamic mechanical analysis and fracture micrographs of EC/PP blends. The addition of maleated PP, for the modification of the interphasial interaction between the PP matrix and the EC fibrils, did not impair the fiber formation substantially.

Sensory Evaluation of Hydroxy Ethyl Cellulose (HEC) in Facial Mask

An equipment test and sensory evaluation were conducted to identify the compatibility and sensory characteristics of HEC in facial masks. These results were then compared to xanthan gum usage. The equipment test results showed that HEC promoted proper tensile capacity in masks which are made from strong structured fabrics such as medium thick, thick and cross woven & homogenous thin mask fabrics. HEC was found to be more compatible with mask fabrics than xanthan gum. HEC improved mask softness and dampness and had an improved water binding and water retention ability compared to xanthan gum. The split face sensory evaluation results demonstrated that sheet masks containing HEC had improved adhesion and lubricity, provided more moisture to the skin, better elasticity and gloss after use and took longer to dry out. Overall, the panel preferred facial masks which contain HEC.

Construction of Photoresponsive Supramolecular Micelles Based on Ethyl Cellulose Graft Copolymer

In this work, a UV-Visible light controlled supramolecular system based on ethyl cellulose （EC） was constructed, combining the host-guest interaction of β-cyclodextrin （β-CD） group and trans-isomer of azobenzene （tAzo） group. To link β-CD to the hydrophobic section, renewable EC was used as macroinitiator to initiate the polymerization of ε-caprolactone （ε-CL） to form biocompatible and biodegradable comb copolymer EC-g-PCL, and β-CD was attached to the end of PCL side chain via click reaction. Meanwhile, hydrophilic PEG-tAzo was obtained by N,N＇-dicyclohexylcarbodiimide （DCC） coupling. Then, the structures of the products were characterized by nuclear magnetic resonance （NMR） and gel permeation chromatography （GPC）. Subsequently, with the formation of inclusion complexes by β-CD and tAzo groups, the obtained EC-g-PCL-β-CD/PEG-tAzo supramolecular system self-assembled in water with hydrophobic EC-g-PCL-β-CD as core and hydrophilic PEG-tAzo as shell. Furthermore, dynamic light scattering （DLS） and transmission electron microscopy （TEM） were utilized to investigate the particle size and size distribution, while NMR and UV-Vis spectra were applied to explore the UV-Visible light stimuli-responsiveness of the micelles.

Electrophoretic deposition of a supercapacitor electrode of activated carbon onto an indium-tin-oxide substrate using ethyl cellulose as a binder

A transparent energy storage device is an essential component for transparent electronics.The increasing demand for high-power devices stimulates the development of transparent supercapacitors with high power density.A transparent electrode for such supercapacitors can be assembled via the electrophoretic deposition of an active material powder with a binder onto a transparent substrate.The properties of the binder critically influence the electrochemical behavior and performance of the resulting electrode.Ethyl cellulose(EC)is known as an eco-friendly,transparent,flexible,and inexpensive material.Here,we fabricated an electrode film with EC binder via electrophoretic deposition on an indium tin oxide(ITO)substrate instead of using the conventional polytetrafluoroethylene(PTFE)binder.The assembled electrodes with EC and PTFE were compared to investigate the feasibility of EC as a binder from different perspectives,including homogeneity,wettability,electrochemical behavior,and mechanical stability.The EC enabled the formation of a homogeneous film composed of smaller particles and with a higher specific capacitance compared with films prepared with PTFE.The annealing improved the adhesion strength of the EC because of its glass transition;however,its hydrophobic nature limited utilization of the active material for charge storage.Subsequent electrochemical activation improved the wettability of the electrode,resulting in an increased capacitance of 60 F g^(-1).Furthermore,even with the lower wettability of EC compared with that of PTFE,better rate performance was possible with the EC electrode.The increased mechanical stability after the annealing process ensured an excellent cycle life of 95%capacitance retention for 15,000 cycles.

Release behavior and kinetic evaluation of berberine hydrochloride from ethyl cellulose/chitosan microspheres

Novel ethyl cellulose/chitosan microspheres （ECCMs） were prepared by the method of w/o/w emulsion and solvent evaporation. The microspheres were spherical, adhesive, and aggregated loosely with a size not bigger than 5 pm. The drug loading efficiency of berberine hydrochloride （BH） loaded in microspheres were affected by chitosan （CS） concentration, EC concentration and the volume ratio of V（CS）/V（EC）. ECCMs prepared had sustained release efficiency on BH which was changed with different preparation parameters. In addition, the pH value of release media had obvious effect on the release character of ECCMs. The release rate of BH from sample B was only a little more than 30% in diluted hydrochloric acid （dHCl） and that was almost 90% in PBS during 24 h. Furthermore, the drug release data were fitted to different kinetic models to analyze the release kinetics and the mechanism from the microspheres. The released results of BH indicated that ECCMs exhibited non-Fickian diffusion mechanism in dHCI and diffusion-controlled drug release based on Fickian diffusion in PBS. So the ECCMs might be an ideal sustained release system especially in dHCl and the drug release was governed by both diffusion of the drug and dissolution of the polymeric network.

STUDIES ON CRITICAL CONCENTRATION OF LIQUID CRYSTALLINE ETHYLCELLULOSE

Critical concentrations of lyotropic liquid crystalline ethylcellulose in more than ten solvents were determined using both Abbe refractometer and polarized microscopy. Critical concentration C-crit of forming Liquid crystal phase decreased with increasing solubility parameter delta of solvent until approaching the delta of polymer. Although the alcohols used as solvents had the same variation rule, the critical concentration values of their solutions were much higher, due to their excessive large hydrogen bond component of delta. The experiments of using mixed solvents which showed good linear relation between C-crit and delta also proved this rule. A technique of Transmission Optical Analysis was first used to estimate the concentration dependence of critical phase transition temperature T-crit of EC, and a T-C phase diagram could be drawn.

Block and Hetero Ethyl Cellulose Graft Copolymers Synthe- sized via Sequent and One-pot ATRP and ＂Click＂ Reactions

Ethyl cellulose graft copolymers with block and hetero side chains, ethyl cellulose graft [polystyrene-b-poly- （ethylene glycol）] [EC-g-（PS-b-PEG）] and ethyl cellulose graft polystyrene and polyethylene glycol [EC-g-（PS-PEG ）] were synthesized by atomic transfer radical polymerization （ATRP） and alkyne-azide ＂click＂ reactions and ＂one-pot＂ ATRP and ＂click＂ reactions, respectively. For the synthesis of EC-g-（PS-b-PEG）, the macroinitiator for ATRP was first synthesized via the esterification of hydroxyl groups of EC with 2-bromoisobutyryl bromide to re- sult ethyl cellulose 2-bromoisobutyryl ester （EC-Br）. The degree of substitution of bromide groups, which deter- mined the graft density, can be tailored by varying the feeding ratios of the hydroxyl groups to 2-bromoisobutyryl bromide. Then ATRP was carried out for preparing EC-g-PS-Br with well-defined length of PS chains. The EC-g-PS-Br copolymers were then converted to EC-g-PS-N3 and then reacted with end alkyne-functionalized PEG via click to result in EC-g-（PS-b-PEG）. The EC-g-（PS-PEG） copolymers were synthesized by converting bromide groups of EC-Br to azide groups （EC-Br-N3） and then by one-pot ATRP and ＂click＂ reactions. The resultant graft copolymers were characterized by FTIR and IH NMR. The results indicate the success of the synthetic procedure of the cellulose grail copolymers with block and hetero side chains.

Etherification of Alkali-pretreated Sugarcane Bagasse Cellulose in Tetrahydrofuran

Sugarcane bagasse(SCB)is an important by-product in the sugar industry.It is a source of cellulose fibers or cellulose for paper mills and textiles factories.In this study,SCB was ethyl etherified in tetrahydrofuran(THF)after alkali pretreatment.The alkali concentration for the pretreatment,the ratio of ethyl bromide(EtBr)to dried SCB in the reaction,reaction time,and temperature were investigated for the etherification of SCB.The ethoxyl content and characterization of the product were determined using headspace gas chromatography(HS-GC),Fourier Transform Infrared(FT-IR)and 13C-NMR spectroscopy,respectively.It was found that SCB was well-etherified with EtBr in alkali-THF.Upon ethylation of SCB,the ethoxyl content of the product was high when the alkali concentration and the ratio of EtBr to dried SCB were controlled from 50%to 75%and 4:1(V/w)to 6:1(V/w),respectively.The reaction occurred optimally when the temperature was controlled below 110℃;above this temperature,the degree of etherification decreased.The thermal stability of ethylated SCB was higher than that of SCB but slightly lower than that of commercial ethyl cellulose.Ethylated SCB has the potential to form composites with many materials because it is soluble in a wide variety of solvents.

Coating Process of Paeonol Sustained Release Pills

[Objectives] To study the coating process of paeonol sustained release pills by extrusion-spheronization method taking ethyl cellulose as the coating material. [Methods] Paeonol pills were made by Auari AW-95 Full Automatic Pill Making Machine. Coating of paeonol sustained release pills was prepared by Auari Mini Pill Polishing Machine. The prescription and process factors of paeonol sustained release pills coating were investigated by single factor experiment and orthogonal experiment. The release of paeonol sustained release pills was determined according to the cumulative release curve of paeonol. [Results] The prepared paeonol sustained release pills released slowly within 24 h, and the release rate reached 80% in 12 h. [Conclusions] The prepared paeonol sustained release pills basically meet the 24 h sustained release standard, and can be further developed and applied.

Transferring Process of RE^(3+) with the Microcapsules Containing P507

thylhexyl phosphonic acid mono-2-ethylhexyl ester (P507) was microencapsulated with ethyl cellulose and calcium alginate respectively.The microcapsules containing P507 can be used to extract and enrich Lu3+,Nd3+,and La3+ from aqueous solutions into them.Because of the immobility of the wall to the extractive agent,it changes the processes that the ions transfer into the agent (core material).Their relative transferring rates can be compared in accordance with permeative coefficiencies.The permeative coefficiencies will vary as the pH of the aqueous solutions is changed.Therefore,the differences of them between two ions can be enlarged in this way.The REP-507 complex can be stripped with 6 mol·L-1 HCl,which should enrich the ions quantitatively.

Development,characterization and solubility enhancement of comparative dissolution study of second generation of solid dispersions and microspheres for poorly water soluble drug

The poor dissolution characteristics of water-insoluble drugs are a major challenge for pharmaceutical scientists.Reduction of the particle size/increase in the surface area of the drug is a widely used and relatively simple method for increasing dissolution rates.The objective of this study was to improve solubility,release and comparability of dissolution of a poorly soluble drug using two different types of formulations(solid dispersions and microspheres).Hydrochlorothiazide was used as a model drug.The solid dispersions and microspheres were prepared by solvent evaporation method using ethyl cellulose,hydroxypropyl methylcellulose in different drug-to-carrier ratios(1:1,1:2 w:w).The prepared formulations were evaluated for interaction study by Fourier transform infrared spectroscopy,differential scanning calorimetry,percentage of practical yield,drug loading,surface morphology by scanning electron microscopy,optical microscopy and in-vitro release studies.The results showed no interaction between the drug and polymer,amorphous state of solid dispersions and microspheres,percentage yield of 42.53%to 78.10%,drug content of 99.60%to 99.64%,good spherical appearance in formulation VI and significant increase in the dissolution rate.

Preparation and characterization of La_(0.8)Sr_(0.04)Ca_(0.16)Co_(0.6)Fe_(0.4)O_(3-δ)-La_(0.9)Sr_(0.1)Ga_(0.8)Mg_(0.2)O_3 composite cathode thin film for SOFC by slurry spin coating

The La0.8Sr0.04Ca0.16Co0.6Fe0.4O3-δ (LSCCoF) and La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) powders were synthesized by glycine-nitrate combustion process and conventional solid-state reaction method, respectively. The LSCCoF-LSGM composite cathode material was successfully elaborated and deposited on dense pellets of the LSGM electrolyte by means of slurry spin-coating process. The cathode films with the best surface morphology and microstructure were obtained when the operating parameters fixed as follows: the content of ethyl cellulose which acted as pore former and binder is 10 wt.%, the content of terpineol which acted as modifier is 5 wt.%, the speed of rotation rate is 3200 r/min and the best post-deposition sintering temperature is 1000°C.

Statistical optimization and in vivo evaluation of colon specific delivery system of herbal rhubarb extract

The present research effort was aimed to develop colon targeted drug delivery system(CTDDS)of rhubarb,herbal drug using a mixed film of pectin and ethyl cellulose(EC).Pectin and ethyl cellulose were mixed in various proportions to coat the core tablet to target colon.The methanolic extract of rhubarb was used and the dose of the extract in each formulation was finalized by estimating the emodin content in it by high performace thin layer chromatography(HPTLC).In vitro drug release,erosion study in presence and absence of pectinase enzyme and release constant(K)of zero order was measured for each formulation.The formulation was optimized by using 32full factorial design.Formulation having 50%pectin as a coating polymer with12%coat weight was selected as an optimized formulation(OF)on the basis of%similarity with maximum desirability but this formulation was not able to retard the release of drug in stomach and upper intestine fully.So it was further coated with Eudragit S100(ES)(3%coat weight).The optimized formulation,coated with ES indicated significant laxative activity on loperamide induced constipation in rats.The results revealed that CTDDS of rhubarb using two combined approaches of biodegrable microflora-activated system and pH-sensitive system exhibited a promising colon targeting performance.